000
FXUS65 KSLC 110439
AFDSLC
Area Forecast Discussion
National Weather Service Salt Lake City UT
1039 PM MDT Thu Aug 10 2017
.SYNOPSIS...Moisture pooled over Arizona will begin to work north
into extreme southern Utah tonight, then continue north across
southern and eastern Utah over the weekend. A drying trend is
forecast beginning next week.
&&
.SHORT TERM (Through 00Z Sunday)...Afternoon convection that
strengthen near the Nevada and Idaho borders with northern Utah
faded quickly this evening with the loss of daytime heating and
the lack of sustainable dynamic support. One last area of loosely
organized convection across northeast Nevada will drift east into
far northwest Utah ahead of a weak shortwave entering the state.
Suspect that this convection will remain on the weak side, though
with the entrance region of the jet over central Utah can not
entirely rule out a strong convective element or two later tonight
or early Friday morning.
Convection will fire up again across the far north Friday
afternoon and evening. The next weak shortwave will track across
northeast Nevada during the day, then cut across extreme northwest
Utah late Friday afternoon and evening. Convection will likely
remain confined to the far north, with a few strong storms
possible.
Down south the leading edge of the returning moisture over Arizona
will skirt the Utah/Arizona border overnight. Light showers/storms
on the Arizona side near Lake Powell will drift into south-
central/southeast Utah during the night. The moisture will
continue north across the southern tier of Utah Friday, then take
a turn into east-central Utah early in the weekend. Convection
will increase in areal coverage with the moisture, with the
potential heavy rain across the far south over the weekend.
.PREVIOUS LONG TERM (After 00z Sunday)...A broad ridge is
centered roughly over Utah at the start of the long term period
with sufficient moisture remaining in place to continue to support
convection. Models shift the ridge east by Sunday eve with a
general swly flow becoming established but any drying looks to
hold off until after Tue.
Guidance indicates additional rounds of nocturnal convection
across the CWA each night thru the weekend with weak passing short
waves. By Tue, GFS and EC differ on the strength of a short wave
passing to our north with the EC sending a cold front into the
north and ushering in a drier westerly flow. The GFS keeps us in
swly flow with a continued drying trend thru mid week.
Trended forecasts towards the warmer GFS but both would pretty
much bring an end to the threat of convection after Tue and other
than token aftn pops over the Wasatch Plateau and Uintas, kept
the forecast dry.
&&
.AVIATION...The lingering showers across northern Utah will
dissipate by midnight and are not expected to impact the terminal
through Friday morning. Light northerly winds at the terminal will
turn back a drainage southeast direction around 06z.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&
$$
CONGER
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